Joining a new company in 2021 as a tech lead. What are your top three pieces of advice l, esp given everyone is fully remote still given Covid-19?

Keep your nose to the wind and don't prematurely update linkedin.

Seconding @SortOfTested's advice.

Further, you're here so that means you probably have opinions. Don't have opinions or political views the first month or so. See how everything works first. The picture people paint you about the company or themselves at the very beginning will very rarely be accurate.

Be nice, approachable, but most importantly, neutral to the fullest extent until you have sussed out where you can "wander" if that makes sense.

Use the first 3 Months with your fresh eyes to analyze the current system.
Do one on one talks and show genuine interest in the opinions of your subjugates. Ask what they do think of the current state of affairs. Ask them what fascinates being a dev and what they like doing and what not. Observe first. Find opportunities, potentials weaknesses and dangers.

Don't confuse the "Lead" with beeing a dick! No, don't come on day two and say everything they do and the tech stack is wrong.

Maybe organize as a welcome a video game match? Among us or counter strike source? 😃

Read the Book "How to win Friends and Influence People"
https://amazon.com/How-Win-Friends-...
How to Win Friends & Influence People: Dale Carnegie ...

Best of luck 🙂